1. Field of the Invention
The present invention concerns a liquid supply device and, more particularly, it relates to a liquid supply device suitable to the supply of an aqueous solution, for example, containing hydrogen peroxide to an oxygen generation system.
2. Description of the Prior Art
It has generally been known oxygen generation system, for example, as disclosed in Japanese Utility Model Publication No. Sho 55-26445 (1980) for decomposing aqueous hydrogen peroxide using a manganese compound such as manganese dioxide or potassium permanganate as the catalyst, or as disclosed in Japanese Patent Publication No. Sho 52-42155 (1977) for decomposing aqueous hydrogen peroxide at a high concentration of from 30 to 50% by using a platinum type catalyst.
However, in the former device using the manganese compound as the catalyst, if the concentration of the aqueous hydrogen peroxide exceeds 5%, the decomposing reaction is taken place at an explosive rate and, accordingly, it is obliged to reduce the concentration of the aqueous hydrogen peroxide to about 3%. However, use of aqueous hydrogen peroxide at such a low concentration, results in a problem that the volume of the aqueous hydrogen peroxide vessel is increased for obtaining a required flow rate of oxygen gas and the size of the oxygen generation system can not be decreased.
Furthermore, in the latter type device using the platinum group catalyst, although it is necessary to increase the catalyst reaction area as great as possible in order to completely decompose aqueous hydrogen peroxide at a restricted flow rate and generate gaseous oxygen efficiently for a long period of time, no such supported catalyst has been known and stable generation of oxygen has been impossible.
In view of the above, the present inventor has already proposed an oxygen generating system using a supported-catalyst comprising a support with a great pore size composed of sintered ceramic grains and a platinum catalyst supported thereon for decomposing aqueous hydrogen peroxide and evolving oxygen (Japanese Patent Application Sho 60-58931; corresponding to allowed U.S. patent application Ser. No. 843,024, filed on Mar. 24, 1986), now U.S. Pat. No. 4,792,435.
The oxygen generating system proposed by the present inventor has various advantageous effects in that it is small in the size and reduced in the weight, as well as capable of supplying oxygen at a sufficient flow rate stably over a long period of time.
However, in the proposed oxygen generating system, since a liquid supply device having a motor-driven tube type pump (peripheral pump) is used for supplying aqueous hydrogen peroxide to the inside of a reaction chamber containing a supported catalyst, it requires an electric power source for driving the pump and results in a problem that the driving control is difficult to cause frequent failures. Furthermore, since noises are resulted upon motor driving, etc., it is not quite satisfactory depending on the application use such as medical use.